期刊
WATER RESOURCES RESEARCH
卷 57, 期 5, 页码 -出版社
AMER GEOPHYSICAL UNION
DOI: 10.1029/2019WR026988
关键词
flow velocity; macropores; preferential flow; soil water; viscous flow
资金
- German Research Association (DFG) [FOR 1598]
Using a unique dataset and film flow model, this study analyzed infiltration events under different soil and land cover conditions. The results showed that film flow was able to predict wetting front velocity and flow parameters effectively, with gravity being the main driving force.
Applying physically based models that include preferential flow (PF) is still very challenging at the catchment scale. A gravity-driven film flow approach could be a promising concept for modeling PF as it only requires a small number of parameters. We tested if this approach can be used for different soils and land covers within a 247 km(2) catchment and if we can find generalizable relationships of the film flow parameters to site or rainfall properties. We used a unique data set from a soil moisture sensor network with 135 instrumented soil profiles in three different geologies (slate, marl, and sandstone) and two land covers (forest and grassland) and fitted the film flow model to around 1,700 infiltration events. The results demonstrate that the physical relationship of film flow was capable to predict wetting front velocity (v) and flow parameters from rainfall input (q(s)) alone. This relationship was pronounced in grassland sites but weaker for forest sites, probably due to heterogeneity of the rainfall input underneath the canopy. Incorporating the water content into the v-q(s) relationship did not improve the quality, but showed that for the film flow the rainfall input and hence gravity is in fact the dominant driver and not capillarity. Furthermore, abstraction of water into the soil matrix during film flow is an important process to be included into the framework with reasonable agreements for marl and sandstone using a multiple linear regression. Film flow and corresponding functional parameter relationships for other regions could improve catchment wide PF modeling in the future.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据